LONDON (AP) — Britain’s government says it will trigger Article 50, signaling Britain’s departure from the European Union, on March 29.

The Department for Exiting the European Union said in a statement that Britain’s permanent representative to the EU, Tim Barrow, informed the European Council President Donald Tusk of the timing on Monday morning. The notification of triggering Article 50 will come in the form of a letter.

Brexit Secretary David Davis said in a statement that the country is “on the threshold of the most important negotiation” for a generation.